Initial Inspection and Diagnostic Overview

Diagnostic Starting Point - Engine Mechanical (5.3L)

Begin the system diagnosis by reviewing the Disassembled Views (5.3L) ([1][2]Diagrams)Disassembled Views (6.0L) ([1][2]Diagrams) , Engine Component Description (5.3L) (Engine Component Description)Engine Component Description (6.0L) (Engine Component Description) , Lubrication Description - Main Pressure Below 55 psi with Cylinder Deactivation (Active Fuel Management) Off (5.3L) (Description and Operation) , Lubrication Description - Main Pressure Above 55 psi with Cylinder Deactivation (Active Fuel Management) Off (5.3L) (Description and Operation) , Lubrication Description - Main Pressure Below 55 psi with Cylinder Deactivation (Active Fuel Management) On (5.3L) (Description and Operation) , Lubrication Description - Main Pressure Above 55 psi with Cylinder Deactivation (Active Fuel Management) On (5.3L) (Description and Operation) and Cylinder Deactivation (Active Fuel Management) System Description (Cylinder Deactivation (Active Fuel Management) System Description). Reviewing the description and operation information helps you determine the correct symptom diagnostic procedure when a condition exists. Reviewing the description and operation information also helps you determine if the condition described by the customer is normal operation. Refer to Symptoms - Engine Mechanical (5.3L) (- Symptoms - Engine Mechanical)Symptoms - Engine Mechanical (6.0L) (- Symptoms - Engine Mechanical) in order to identify the correct procedure for diagnosing the system and where the procedure is located.